


Sincerely, the stranger you call brother

by Satsuki_Miya



Category: Assassination Classroom
Genre: Angst, Brotherly Love, Brothers AU, Character Development, Comedy, Overwork, Sassy Karma, Secrets, Sickfic, alternative universe, follows canon at first, mother hen Asano, secretly brothers
Language: English
Status: In-Progress
Published: 2018-11-04
Updated: 2018-11-04
Packaged: 2019-08-18 19:18:15
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 2
Words: 2,981
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/16523072
Author URL: https://archiveofourown.org/users/Satsuki_Miya/pseuds/Satsuki_Miya
Summary: Karma knows one thing. Having an older sibling is no fun. But if that older sibling is actually a genius, school's idol, the student council president and secretly a mother hen, things could get hilarious. Especially if no one knew. Or rather, only if no one knew. Because if anyone was to find out they were anything more than schoolmates, everything would break.





	1. Chapter 1

**Author's Note:**

> This fanfic is an AU where Karma and Asano are brothers but for a certain reason (you're gonna find out), they must keep it secret. It's kinda cheesy at first coz I started it when I was 16 (oh my god, so embarrassing) but I hope you're gonna like it anyway :)
> 
> Btw, fhe first few chapters will be flashbacks from one year ago when our main characters were in second years. So Karma's not in the E class yet.

Asano's P.O.V.

He was late.

It was 15:07 now and I still didn't see anyone coming. Usually, both of us met at this secluded place, hidden in the middle of probably nowhere, at exactly three p.m. Without fail. Could he be having some troubles? Or was he being followed? Not sure of what to do, I took out my phone to see if there was any message from him. None. So I already wanted to write him myself.

However, as I started typing the letters, I got a glimpse of red and immediately put the gadget back into my pocket, searching for the boy with my eyes.

And there he was - with a cut on his cheek and bruise on an arm. I couldn't see the bruise but judging from the way he let the limb down instead of putting it into his pocket, I could guess that it hurt to even move it.

"Karma," I walked towards him, examining every part of his body for any other injuries. "What the hell did you do? Another fight?"

The boy just clicked his tongue and wiped the blood away. "They were picking on senpai so I just stood up for him."

"Who ' _they_ '?! What senpai? And anyway, did you have to fight again? I told you many times not to do stupid things," I sighed, taking out a handkerchief and some band-aids. This little idiot always got himself hurt - any time, any way possible, without fail - so I keep it for sure.

"I saw some assholes bullying a third year from class E so I went there and beat the shit out of them."

"Watch your language, kid," I scolded him while putting the band-aid on the side of his face.

"I am not a kid," he tried to grunt but didn't manage to as I was in the control of his facial muscles right now (I mean I was holding his face).

"You are one year younger than me."

"Theoretically not since I am in the same year as you."

"Skipping grades doesn't make you older, " And I patted his head to emphasize the height difference (seven centimeters).

Knowing that he won't win this argument, he gave up: "Touché,"

Having finished treating the wound, I narrowed eyebrows and flicked the latter on the forehead. He whined and started rubbing the spot which was now turning red.

"Who were the bullies? I mean which class," the very fact that he fought for a member of class E made me uneasy. His answer, however, made me feel something close to terror:

"Class A," the redhead mumbled, aware of how I would react.

Closing my eyes, I started out with a serious tone: "Speaking of shit, you just got into some."

"Wow, how did you figure that out, mister Know-it-all?" That stupid remark made me want to kill him but in this country, that was illegal. Such an insolent kid. Rebellious and violent to that. I guess the lack of supervision influenced him to the bad.

"You know your teacher or even the chairman is going to punish you for that," I said as we sat down on the grass.

Just by the way, this place was in the middle of forest which was easy to get in but hard to get out. That's exactly why we have chosen it. No one would ever dare to step into it, let alone go this deep in. Me and Karma are an exception though, as memorizing the way here was a piece of cake. Actually, we have memorized the whole forest.

And as for why we had to take such measurements - It was simple. We couldn't afford to let anyone find out about our blood relation. Not the students, the teachers and most certainly not our father. This was a complicated matter so for now, I will put that aside.

"Suspension at worst," my younger brother nodded, lying down. "But you know, Ono-sensei is a good person. He said that he would be on my side if I were right. And I were - bullying the weaker ones is ridiculous. If they want to pick a fight, why don't they choose someone strong?"

Dear God, this idiot was too childish and naive. First of all, that's just how this school works. Actually, this system is very effective and to look down on the failures - wasn't it fun?

Either way, that Ono-sensei of his was obviously just a fake who made use of the situation. Karma may be violent and uncontrollable but he is a genius. Even though he is barely thirteen - no one knows that by the way - he understands all of the stuff for fourteen years olds (me) and perhaps even further. We have it in our genes, most likely. Karma might just have been able to take over my rank number one in the school if he tried harder. But he won't because he is an arrogant, lazy ass.

Anyway, back to the subject - Karma was a wonderful way for that teacher to make himself a good name, having "brought up" a student with such terrific academical success.

"You shouldn't rely on that teacher. He doesn't sound trustworthy to me."

But the boy shook his head: "I trust him, he always supports me."

Well that was some surprise. He has never trusted anyone else besides me. And it kind of hurt my pride.

"Do you doubt my words?"

"No, I just believe in my own opinion and feelings. That's what you taught me, wasn't it?"

"I regret teaching you that. You would be much more obedient if I didn't," saying that in a joking manner, I ruffled his hair.

It was a nice change from the every day facade he had to keep. Not having to be the perfect council president. Not having to stay on guard. Or to pretend that I didn't see or even know my own brother.

"Hey, Asan-" Karma called me but I stopped him before he could say anything else.

"Cut the surname thing. We are alone now,"

And there it was. That smug, plotting grin.

"Yeah, right,  _onii-chan_ ," He said with a sweet, playful tone. I made a disgusted grimace, feeling very sick. That was most definitely _not_  what I meant.

"Ahaha, sorry. Should I call you Gakushu-nii if you insist on me being polite and respectful to my older brother? Or Gaku-niichan to make it more affectionate?"

Bleh.

Poking his side (he was ticklish), I teased him. "Only if you wish to be called Karma-chan from now on,"

"God I want to throw up.

Exactly.

And the two of us joined a staring contest. I don't know how but it turned out into a tickling war.

It has always been like this - me taking care of his health, he taking care of my sanity (now, it's not that easy to live under pressure with a gruesome father, is it?) and the two of us half-heartedly talking.

It was something we could never afford to do if we weren't together and alone. If we hadn't lied to everyone else - even our parents.

To summarize - dad and mom divorced when I was six and Karma five. They literally went after each other's neck. That having been decided by judges, the chairman (father) got me into his care and Karma stayed with mother. Though at that time, Karma's name was different.

We promised each other to stay in touch, secretly, and until now, we did so. In order to fulfill that promise, he had to get into the same school as me. As I was forced by the chairman to attend his school, he followed me.

And here's where the problem lies - if the chairman knew that Karma was his second son, who knows how he would react? Taking into account that he hated their mother, he would probably make the boy's life living hell.

I tried convincing him to go somewhere else, but - kids. And Karma especially. He didn't take a 'no' for an answer and applied anyway.

About the names - father didn't know the name Akabane - it was our mother's lover surname. For some reason, he didn't mind taking 'Akabane' but he despised his initial name given by mother. So he stuck with the thought up name Karma for ten years. To be honest, I liked it better too.

I think that more or less explains the situation. Nobody knows of this big lie of ours - mother is always overseas and we have been hiding this from father. Karma skipped one year to be in the same class as me, took exams to this school to be with me, learned Latin so that we would be able to speak with each other when needed (hardly anyone knows Latin so it was a perfect choice). Well, that was all many years ago when he was still a nice, (kind of if you didn't count the violence - he has always loved fighting. Though I do too.) innocent and cute kid.

He grew up into a rebellious shit.

_(I actually remember how respectfully and affectionately he looked up to me?! Like he was all 'Gakushu-nii! Show me this! Let's go there! You are so amazing!' And now it's like: 'Fuck yourself, I'm gonna have it my own way"_

_Like... What the hell?!)_


	2. Chapter 2

**Summary for the Chapter:**

> Domestic sibling fights :D I don't know.

Karma's P.O.V.

Gakushu said he would go home with me and stay there until six. The chairman was allegedly going to be out of the town for two days - so it wasn't a problem. And his stepmother - she was like a dead bug, not voicing out or questioning anything. So she couldn't care less about the teen returning later.

Really, this worrywart. I could fend for myself just fine - I had learned to cook long ago and taking care of cuts and bruises - that's how I grew up. But I was kind of glad that he suggested it. It has been quite lonely in here lately.

"Go take put some ice on the bruise, I will prepare dinner," The strawberry blond ordered as we entered the vacant house I lived in. I didn't bother to say 'I'm home' since nobody was there to welcome me back.

"Is there anything you can't see?" I was reffering to the bruise - it was hidden under my sleeves so how come he knew?

Sending me an annoyed look, he answered: "I can't see why you have become such a pain in the bottom part of a body."

We walked to the kitchen. The first thing he did was hand me an ice pack.

"Haha, keeping that polite and diplomatic attitude even now?" yeah, the chairman didn't let him spurt out anything of such low manner after all. But hey, we were alone now. We could be behaving however we wanted and not give any shit.

Gakushu ignored me, now opening the fridge to get the ingredients for perhaps making a real meal. He seemed irritated by what he saw - well, I haven't been out for groceries for quite a long time now. Deciding that he would somehow manage with a lettuce and tomato, he took out a knife and started cutting the vegetable.

"Come on, you love this 'pain in bottom part of a body' anyway, don't you?" I playfully asked, tilting my head and staring into his violet eyes. Violet and gold, those were the colours of kings, no?

"Yeah, yeah. Now get your ass on a chair and stop bothering me. I don't want to cut myself and then massacre you if I snap."

Grinning, I sat down. It always amazed me how different he was at school and with me. In that place, he was polite but intimidating when angered, with me he was rude as hell and fun to joke with. Though he was still strict af and liked to dote me.

I observed my (unfortunately) older brother. This was such a nostalgic sight. The first time Gakushu came to this house and made me a meal was when we were were lik nine. I could more or less cook by then (It was edible but tasteless. What would you expect from an eight? nine? years old kid?) but the latter insisted.

It was in winter if I remembered right. The chairman wasn't going to return home until midnight and Gakushu got fed up with being with that stupid stepmom-servant and decided to visit me.

"Gaku-nii," calling him like that at the time, I gaped at the boy standing before the doors, almost frozen to the bone and covered in snow. "Wh-what are you doing here?!"

Knowing that nobody was home, he came in and simply stated: "I will be staying here for a while,"

With that, I handed him a blanket and both of us sat by the heater. We chatted about what has happened, how we felt and what we wanted to do. That was also when we decided to meet up in secret either in a forest or at my place (Since mother and her lover were rarely home. And if they did return, I would always message him about that.) Also, he suggested that we learn a language which only we will be able to understand.

It came in handy as even the chairman didn't know Latin.

Since then, he often stayed with me and we took turns cooking. Gakushu would tell his friends he was going home early to buy some books or that he was going to a library. The chairman didn't really care so it was working just fine. And anyway, that man never returned before seven p.m. Oh and to make sure no one would recognize him, Gakushu always brought a jumper with a hood with him and wore it when going in and out of my house.

Pfff. He looked ridiculous in hoods. Unlike the handsome me.

"Karma! Stop spacing out or I'm going to spill this into your face. And I assure you, third-degree burns are not pleasant," Suddenly, the male stood before me with a bowl of the most simple food in the world.

"Seriously? No meat? I'm going to die from hunger you know," faking a pout, I objected.

The blond was giving me a glare: "That's a punishment. For getting into a fight and not buying groceries."

"You could have gone get it," playing a sulking kid, I crossed my arms.

"Why didn't you do that?"

"Making an injured person run an errand? How heartless."

"Making your _older_  brother run an errand? How cheeky."

And we burnt each other with eyes, not saying anything for a whole minute.

"Get the fuck out of my way, this is heavy," the idiot finally gave up and averted his eyes. I internally grinned.

"Eeh? But I am getting sleepy, I think I'm gonna take a nap now-"

Losing his temper, he lifted his leg to kick me. I could literally see the murderous aura around him and the violet orbs were getting dark too. However, I had good reflexes from all the street fight. Catching the leg with my hands, I laughed: "Now, now, that's dangerous, you know,  _nii-chan_."

"I'm going to kill you," my brother hissed.

"Try if you can," and with that, he put the bowl back on the kitchen stove and ran after me. I did my best to avoid getting hurt anymore so all I did was run away.

Ahaha. Ha. Ha...

I might have overdone it.

"You little shit!" He grabbed my shirt and as I tried to jerk away, both of us stumbled and he fell on me. Oh damn, I was pinned down to the ground. Analyzing the situation, I came to this conclusion: I had two options - play dead or become dead.

Deciding to go with the former, I closed my eyes and pretended to be unconscious. I was pretty sure it would work because no matter how pissed off he Gakushu got, he still cared. How considerate.

"Karma..." my brother seethed and lifted himself from me. I don't know how he looked as I was playing dead but judging from the long pause, he was probably confused.

"Hey, idiot," his voice started sounding worried. "Hey, what's wrong?" he lightly slapped my cheek. Ouch.

I did my best to hold back the urge to laugh my ass off. I took advantage of Gakushu letting down his guard, grabbed his arm and shoved him under, with me now pinning the elder boy down.

"I won," giggling, I declared.

Gakushu's face changed from surprise to realization, relief and then displeasure: "You shitfaced dumbass. And here I hoped you hit your head and died," He sighed, relaxing his body in the 'I surrender' way. "That was a dirty trick." The way he looked made me feel a little bit guilty. I guess scaring him like this wasn't the best idea.

"Sorry, I-" but before I could finish that, he did the same thing as me just a while ago.

Now I was down again with the strawberry blond above and a victorious smile on lips: "Who is it that won?"

He was strong. But I have learned how to cope with stronger opponents. Lifting my hips, Gakushu's balance shifted to the front and with that, I threw him off me so we were now lying two meters from each other.

"I guess it's a draw," I wasn't really satisfied with the results but as my body still hurt, fighting any more would be unwise. Especially with my older brother - he was a quite a monster both in psychical abilities and in studies.

We helped each other stand up and returned back to the kitchen.

* * *

The food was cold and far from sufficient. I mean, how could you survive without meat?! The oh so awesome meat?! But, you see, eating it with him, it tasted better than anything else.

**Author's Note:**

> I swear... it's gonna get better.


End file.
